//
//  UIBarButtonItem+Extension.swift
//  05.08--weibo
//
//  Created by fennyYang on 16/5/18.
//  Copyright © 2016年 a. All rights reserved.
//

import UIKit

// 扩展UIBarButtonItem
extension UIBarButtonItem
{
     // 方案4，便利构造函数，在扩展中只能添加便利构造函数
     convenience init(imageName: String, target: AnyObject?, action: Selector)
     {
          // 创建按钮
          let button = UIButton()

          button.setImage(UIImage(named: imageName), forState: UIControlState.Normal)

          button.setImage(UIImage(named: imageName + "_highlighted"), forState: UIControlState.Highlighted)

          button.sizeToFit()

          // 设置点击事件
          button.addTarget(target, action: action, forControlEvents: UIControlEvents.TouchUpInside)

          // 创建UIBarButtonItem，需要调用自己的指定构造函数
          self.init(customView: button)
     }


     // 方案3，创建带按钮的UIBarButtonItem，class表示类方法，类名.方法名()
     class func createBarButtonItem(imageName: String) -> UIBarButtonItem
     {
          let button = UIButton()

          button.setImage(UIImage(named: imageName), forState: UIControlState.Normal)

          button.setImage(UIImage(named: imageName + "_highlighted"), forState: UIControlState.Highlighted)

          button.sizeToFit() // 让控件根据里面的内容设置大小

          return UIBarButtonItem(customView: button)
     }
}














































